Clinical Effectiveness of Regdanvimab Treatment for Mild-to-Moderate COVID-19: A Retrospective Cohort Study

Background: In a Phase III study, regdanvimab (CT-P59) reduced the risk of hospitalization or death versus placebo in patients with mild-to-moderate coronavirus disease 2019 (COVID-19). Purpose: We performed a retrospective cohort study of patients with COVID-19 to examine the effect of regdanvimab versus standard of care (SoC) on oxygen saturation. Methods: We reviewed patients with mild-to-moderate COVID-19 confirmed by reverse transcriptionpolymerase chain reaction at a single hospital in the Republic of Korea. The primary efficacy end point was the proportion of patients deteriorating with peripheral capillary oxygen saturation < 94% on room air up to day 28. Results: A total of 127 patients were treated for COVID-19 with regdanvimab, 190 with SoC. The proportion of patients deteriorating with peripheral capillary oxygen saturation < 94% on room air up to day 28 was 13.4% with regdanvimab and 39.5% with SoC ( P < 0.0 0 01); median time (range) until sustained recovery of fever was 2.0 (0.2-14.8) and 4.2 (0.1-17.1) days, respectively. Supplemental oxygen was required by 23.6% of patients with regdanvimab and 52.1% with SoC ( P < 0.0 0 01) for a mean of 6.3 and 8.7 days, respectively ( P = 0.0113); no patients needed mechanical ventilation. Compared with SoC, hospitalization was shorter with regdanvimab (mean = 11.1 vs 13.6 days; 63.8% vs 31.6% discharged within 11 days; both P values < 0.0 0 01). Fewer regdanvimab-treated patients required remdesivir (14.2% vs 43.2%; P < 0.0 0 01). There were no deaths. Two patients had adverse reactions with regdanvimab. Conclusions: This real-world study indicates that regdanvimab can prevent deterioration in patients with mild-to-moderate COVID-19. (